Which Material Box Cooler Is Better For My Vessel - Aluminum Brass Or Copper-Nickel?
Aluminum Brass vs 90/10 Copper-Nickel Box Cooler Full Comparison & Selection Guide
Core Difference Overview
The two most common tube materials for box coolers are aluminum brass (Admiralty brass) and 90/10 copper-nickel (CuNi 90/10). The choice mainly depends on your sailing waters, maintenance budget, route and vessel type.
1. Performance Comparison Table
| Comparison Item | Aluminum Brass | 90/10 Copper-Nickel |
|---|---|---|
| Heat conductivity | Higher, smaller tube bundle for same cooling load | Lower; needs slightly larger heat exchange area |
| Anti-erosion (sand/silty water) | Poor, max safe seawater velocity 2.5m/s; easy to erode in muddy estuary water | Excellent, max velocity 3.0m/s, tolerates sediment-laden seawater |
| Anti-biofouling | Must be fully coated; natural copper ion release blocked | Uncoated tubes release trace copper ions to restrain barnacles/mussels naturally |
| Galvanic corrosion risk with steel sea chest | High. Bare tube creates huge potential gap with steel; coating damage triggers rapid steel pitting | Low mild potential difference, much lower galvanic corrosion risk |
| Sulfide polluted harbor water | Prone to dezincification, tube cracking/leaking | Stable, no dezincification failure |
| Drydock maintenance workload | High: regular coating inspection, touch-up and recoating | Low: no tube coating required, only check sacrificial anodes |
| Initial cost | Cheaper raw material & manufacturing | Higher upfront purchase cost |
2. Aluminum Brass – Suitable Scenarios & Drawbacks
Advantages
Better heat transfer, compact size to save sea chest installation space
Lower one-time procurement cost for new shipbuilding
Good performance in clean open coastal seawater with no sediment
Disadvantages
Mandatory full tube anti-corrosion coating; any scratch will cause severe galvanic corrosion on steel sea chest
Cannot adapt to river-estuary mixed water, dredging areas or silty water intake
Poor resistance to stagnant polluted port water containing sulfide
Extra drydock cost for coating repair every cycle
Best Vessels to Choose Aluminum Brass
Short-distance coastal cargo ships, fishing boats, yachts operating in clear offshore seawater, small budget newbuilds with clean water intake.
3. 90/10 Copper-Nickel – Suitable Scenarios & Drawbacks
Advantages
Outstanding anti-erosion for muddy, sandy and river-sea mixed water
Tubes work without coating, eliminating coating repair workload
Natural anti-fouling ability, reduces reliance on ICAF system
Stable in dirty, sulfide-rich inner harbor water, no dezincification risk
Wide flow adaptability for ocean-going large vessels
Disadvantages
Lower thermal conductivity, requires a slightly bigger cooler size
Higher initial material cost
Best Vessels to Choose Copper-Nickel
Ocean-going cargo ships, tugboats, dredgers, river-sea through vessels, long-trading ships, vessels frequently berthing in polluted ports.
4. Simple Direct Selection Advice
Pick Aluminum Brass if all below match:
Your ship sails short coastal routes with clear, sediment-free seawater
You want to cut initial equipment investment
Strict regular drydock coating maintenance can be guaranteed
Pick 90/10 Copper-Nickel if any condition applies:
Vessel navigates estuaries, dredging zones or silty river-sea mixed waters
Long ocean voyages with long drydock intervals
Hope to reduce corrosion & fouling maintenance costs in long run
Frequently berths in polluted, sulfide-rich domestic or international ports
Extra Supplementary Note
70/30 copper-nickel has stronger anti-erosion capacity but far higher price. It is only used for naval ships and high-speed special crafts, not standard for commercial medium cargo vessels.
